from nltk import corpus
len(dir(corpus)), dir(corpus)[:15]
(193, ['AlignedCorpusReader', 'AlpinoCorpusReader', 'BNCCorpusReader', 'BracketParseCorpusReader', 'CHILDESCorpusReader', 'CMUDictCorpusReader', 'CategorizedBracketParseCorpusReader', 'CategorizedCorpusReader', 'CategorizedPlaintextCorpusReader', 'CategorizedSentencesCorpusReader', 'CategorizedTaggedCorpusReader', 'ChasenCorpusReader', 'ChunkedCorpusReader', 'ComparativeSentencesCorpusReader', 'ConllChunkCorpusReader'])